In an existing communications network that is based on a wavelength division multiplexing (WDM) technology, to complete optical-electrical-optical conversion, each node in the network still uses a manner of processing information by using an electrical signal to exchange signals. With respect to meeting high-speed and large-capacity requirements, an electronic component in each node has disadvantages such as a bandwidth limitation, a clock offset, serious crosstalk, and high power consumption; as a result, a phenomenon of an “electronic bottleneck” arises in the communications network. To solve this problem, people propose an All-Optical Network (AON) concept. An All-Optical Network has become a first choice in next-generation high-speed broadband networks because of good transparency, wavelength routing feature, compatibility, and scalability.
An optical cross connection (OXC) is a core component in the all-optical network. The optical cross connection and components and devices such as an optical add/drop multiplexer (OADM), an erbium-doped fiber amplifier (EDFA), an attenuator, and an optical fiber form the all-optical network. The OXC exchanges an all-optical signal, and the OXC interconnects specified wavelengths on a network node, so that a wavelength resource is utilized effectively, and wavelength reuse is implemented, that is, a small quantity of wavelengths are used to interconnect a large quantity of network nodes. When the optical fiber is interrupted or a service fails, the OXC can automatically complete operations such as fault isolation, route reselection, and network reconfiguration, so that the service is not interrupted. That is, the OXC has functions such as route selection for a high-speed optical signal and network recovery.
Currently in the market, there is an OXC that is based on a liquid crystal (LC) and a polarization beam splitter (PBS). As shown in FIG. 1, the OXC mainly includes an optical collimator, a displayer, a PBS array, and an LC array. The optical collimator is configured to input and output light, the displayer is configured to convert the input light into same polarized light and couple polarized light from an output end into the optical collimator, the PBS array is configured to split and combine the polarized light, and the LC array is configured to control a polarization direction of the light. A polarization direction of the light on each node is controlled by controlling a voltage of the LC array, thereby implementing transmission of any beam of input light to a required output port. According to the technical solution, there is a great difficulty in assembly, a volume is large, and costs are high.